Over the years many innovators have become intrigued by the prospect of economically harvesting power from water currents such as from rivers where current flow is unidirectional, and estuaries where current direction may reverse with the tide. In that connection various floating devices have been proposed for reacting against the current to turn a shaft which is coupled to a rotary load. However, it is clear that among such prior art current motors none has become or remains popular, nor is any now put to widespread use in spite of the interest and the potentiality. In the opinion of the present inventor, the fact that the prior innovators in the field have not produced a presently successful, popular current motor has generated commonly accepted wisdom that water wheels are no longer an economical way of generating power, to the detriment of society.